With the above cited kind of bearings, it has to be avoided that the radially inner half-races come loose during the bearing transfer and assembly operations, as well as while the assembled bearing is mounted on the vehicle wheel hub.
Known systems provide a provisional retaining means such as discussed in the introductory part of Italian Patent application No. TO94A000596, to the same Applicant. Such solutions have a drawback in that costly additional operations are required in order to machine suitable retaining seats in the bearing half-races to allow engagement of said provisional retaining means. Or, costly apparatuses have to be specifically implemented for handling such provisional retaining means. In some cases, besides being costly, said additional machining operations have the further drawback of weakening the half-races.